Do you know when this problem began (when you did the uninstall I imagine)? Try a System Restore to a point in time BEFORE the problem began. Here's the procedure: http://www.howtogeek.com/howto/windows-vista/using-windows-vista-system-restore/. Be sure to check the box to show more than 5 days of restore points. If the first attempt fails, then try an earlier point or two. NOTE: You will have to re-install any software and updates you installed between now and the restore point, but you can use Windows Update for the updates. Use the recovery disk if the system prompt doesn’t work. The recovery disk works a bit different from the above procedures but if you follow the prompts from the System Restore menu option with the above information you should be able to restore with no problems. This should undo the uninstallation and bring Paper Port back.
Now you need to just install your printer. When it says the program is already installed I assume it is referring to Paper Port and not some other software (just skip over that part and continue). Just go to Start / Control Panel / Printers and click on Add Printer and follow the instructions. You may not need to install any additional software - though you may need to install drivers for the printer (which you may need to get from the manufacturer's web site). Follow both the Add printer guidelines AND the documentation that came with the printer (or get the infomration from the printer's web site or contact their technical support department for assistance with the installation).
I hope this helps. Keep me posted.
Good luck!
Lorien - MCSE/MCSA/Network+/A+ --- If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.